Revert of Implement approx-match support in image filter saveLayer() offscreen. (patchset #31 id:590001 of https://codereview.chromium.org/1034733002/)

Reason for revert:
Spoke to Stephen about this. Reverting because failing debug builds:

https://uberchromegw.corp.google.com/i/client.skia/builders/Test-Mac10.9-Clang-MacMini6.2-GPU-HD4000-x86_64-Debug/builds/51
https://uberchromegw.corp.google.com/i/client.skia/builders/Test-Ubuntu-GCC-ShuttleA-GPU-GTX660-x86_64-Debug/builds/54

Original issue's description:
> Implement approx-match support in image filter saveLayer() offscreen.
>
> Currently, the GPU-side image filter implementation creates
> exact-match textures for the offscreen backing stores for
> saveLayer().  This is because several filters have GPU
> implementations which depend on the texture coordinates
> being 0..1.
>
> The fix is three-fold:
>
> 1) Store the actual requested size in the SkGpuDevice, so
> that when wrapping it in an SkBitmap for passing to
> filterImage(), we can give it the original size.
> 2) Fix the filters (SkMagnifierImageFilter,
> SkLightingImageFilter, SkMatrixConvolutionImageFilter,
> SkMatrixImageFilter) whose GPU implementation depends on
> 0..1 texture coordinates.
> 3) Remove the exception for GPU-side image filters in
> SkCanvas::internalSaveLayer().
>
> For the lighting filters, there were two bugs which were
> cancelling each other out: the sobel filter matrix was
> being computed upside down, but then we'd negate the
> resulting normal. This worked fine in the exact-match case,
> but in the approx-match case we'd sample garbage along
> the edge pixels. Also, we never implemented the edge pixels
> according to spec in the GPU case. It requires a
> different fragment shader for each edge of the nine-patch,
> which meant we couldn't use asFragmentProcessor(), and had
> to implement the drawing via a filterImageGPU() override.
> In order to avoid polluting the public API, I inserted a
> new base class, SkLightingImageFilterInternal above
> Sk[Diffuse|Specular]LightingImageFilter to handle the
> implementation.
>
> For the SkMatrixConvolutionImageFilter, it seems the
> GLSL clamp() function occasionally returns values outside
> the clamped range, resulting in access of garbage
> texels even in GL_NEAREST. The fix here is to clamp to a
> rect inset by half a texel. There was also a bug in
> the unpremultiply step when fConvolveAlpha is false.
>
> For SkMatrixImageFilter, the fix was to make the generic
> draw path be more careful about when to use texture domain.
> If the bitmap already has a texture, use texture domain
> if the srcRect is smaller than the entire texture (not
> the entire bitmap).
>
> N.B.: this change will cause some minor pixel diffs in the
> GPU results of the following GMs (and possibly more):
> matriximagefilter, matrixconvolution, imagefiltersscaled,
> lighting, imagemagnifier, filterfastbounds,
> complexclip_aa_Layer_invert, complexclip_aa_layer,
> complexclip_bw_layer_invert, complexclip_bw_layer.
>
> BUG=skia:3532
>
> Committed: https://skia.googlesource.com/skia/+/b97dafefe63ea0a1bbce8e8b209f4920983fb8b9
>
> Committed: https://skia.googlesource.com/skia/+/f5f8518fe0bbd2703e4ffc1b11ad7b4312ff7641
>
> Committed: https://skia.googlesource.com/skia/+/46112cf2a7c7307f1c9eebb5f881cbda15aa460c

TBR=bsalomon@google.com,reed@chromium.org,senorblanco@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:3532

Review URL: https://codereview.chromium.org/1057693002

1 files changed, 11 insertions, 40 deletions

diff --git a/src/effects/SkMagnifierImageFilter.cpp b/src/effects/SkMagnifierImageFilter.cpp
index 6d2ee01d52..622713d796 100644
--- a/src/effects/SkMagnifierImageFilter.cpp
+++ b/src/effects/SkMagnifierImageFilter.cpp
@@ -25,7 +25,6 @@ class GrMagnifierEffect : public GrSingleTextureEffect {
 
 public:
     static GrFragmentProcessor* Create(GrTexture* texture,
-                                       const SkRect& bounds,
                                        float xOffset,
                                        float yOffset,
                                        float xInvZoom,
@@ -33,7 +32,6 @@ public:
                                        float xInvInset,
                                        float yInvInset) {
         return SkNEW_ARGS(GrMagnifierEffect, (texture,
-                                              bounds,
                                               xOffset,
                                               yOffset,
                                               xInvZoom,
@@ -50,22 +48,15 @@ public:
 
     GrGLFragmentProcessor* createGLInstance() const override;
 
-    const SkRect& bounds() const { return fBounds; }    // Bounds of source image.
-    // Offset to apply to zoomed pixels, (srcRect position / texture size).
     float x_offset() const { return fXOffset; }
     float y_offset() const { return fYOffset; }
-
-    // Scale to apply to zoomed pixels (srcRect size / bounds size).
     float x_inv_zoom() const { return fXInvZoom; }
     float y_inv_zoom() const { return fYInvZoom; }
-
-    // 1/radius over which to transition from unzoomed to zoomed pixels (bounds size / inset).
     float x_inv_inset() const { return fXInvInset; }
     float y_inv_inset() const { return fYInvInset; }
 
 private:
     GrMagnifierEffect(GrTexture* texture,
-                      const SkRect& bounds,
                       float xOffset,
                       float yOffset,
                       float xInvZoom,
@@ -73,7 +64,6 @@ private:
                       float xInvInset,
                       float yInvInset)
         : GrSingleTextureEffect(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture))
-        , fBounds(bounds)
         , fXOffset(xOffset)
         , fYOffset(yOffset)
         , fXInvZoom(xInvZoom)
@@ -89,7 +79,6 @@ private:
 
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 
-    SkRect fBounds;
     float fXOffset;
     float fYOffset;
     float fXInvZoom;
@@ -120,7 +109,6 @@ private:
     UniformHandle       fOffsetVar;
     UniformHandle       fInvZoomVar;
     UniformHandle       fInvInsetVar;
-    UniformHandle       fBoundsVar;
 
     typedef GrGLFragmentProcessor INHERITED;
 };
@@ -146,10 +134,6 @@ void GrGLMagnifierEffect::emitCode(GrGLFPBuilder* builder,
         GrGLProgramBuilder::kFragment_Visibility |
         GrGLProgramBuilder::kVertex_Visibility,
         kVec2f_GrSLType, kDefault_GrSLPrecision, "InvInset");
-    fBoundsVar = builder->addUniform(
-        GrGLProgramBuilder::kFragment_Visibility |
-        GrGLProgramBuilder::kVertex_Visibility,
-        kVec4f_GrSLType, kDefault_GrSLPrecision, "Bounds");
 
     GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
     SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
@@ -158,9 +142,9 @@ void GrGLMagnifierEffect::emitCode(GrGLFPBuilder* builder,
                            builder->getUniformCStr(fOffsetVar),
                            coords2D.c_str(),
                            builder->getUniformCStr(fInvZoomVar));
-    const char* bounds = builder->getUniformCStr(fBoundsVar);
-    fsBuilder->codeAppendf("\t\tvec2 delta = (coord - %s.xy) * %s.zw;\n", bounds, bounds);
-    fsBuilder->codeAppendf("\t\tdelta = min(delta, vec2(1.0, 1.0) - delta);\n");
+
+    fsBuilder->codeAppend("\t\tvec2 delta = min(coord, vec2(1.0, 1.0) - coord);\n");
+
     fsBuilder->codeAppendf("\t\tdelta = delta * %s;\n", builder->getUniformCStr(fInvInsetVar));
 
     fsBuilder->codeAppend("\t\tfloat weight = 0.0;\n");
@@ -191,8 +175,6 @@ void GrGLMagnifierEffect::setData(const GrGLProgramDataManager& pdman,
     pdman.set2f(fOffsetVar, zoom.x_offset(), zoom.y_offset());
     pdman.set2f(fInvZoomVar, zoom.x_inv_zoom(), zoom.y_inv_zoom());
     pdman.set2f(fInvInsetVar, zoom.x_inv_inset(), zoom.y_inv_inset());
-    pdman.set4f(fBoundsVar, zoom.bounds().x(), zoom.bounds().y(),
-                            zoom.bounds().width(), zoom.bounds().height());
 }
 
 /////////////////////////////////////////////////////////////////////
@@ -224,7 +206,6 @@ GrFragmentProcessor* GrMagnifierEffect::TestCreate(SkRandom* random,
 
     GrFragmentProcessor* effect = GrMagnifierEffect::Create(
         texture,
-        SkRect::MakeWH(SkIntToScalar(kMaxWidth), SkIntToScalar(kMaxHeight)),
         (float) width / texture->width(),
         (float) height / texture->height(),
         texture->width() / (float) x,
@@ -239,8 +220,7 @@ GrFragmentProcessor* GrMagnifierEffect::TestCreate(SkRandom* random,
 
 bool GrMagnifierEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrMagnifierEffect& s = sBase.cast<GrMagnifierEffect>();
-    return (this->fBounds == s.fBounds &&
-            this->fXOffset == s.fXOffset &&
+    return (this->fXOffset == s.fXOffset &&
             this->fYOffset == s.fYOffset &&
             this->fXInvZoom == s.fXInvZoom &&
             this->fYInvZoom == s.fYInvZoom &&
@@ -278,27 +258,18 @@ SkMagnifierImageFilter::SkMagnifierImageFilter(const SkRect& srcRect, SkScalar i
 
 #if SK_SUPPORT_GPU
 bool SkMagnifierImageFilter::asFragmentProcessor(GrFragmentProcessor** fp, GrTexture* texture,
-                                                 const SkMatrix&, const SkIRect&bounds) const {
+                                                 const SkMatrix&, const SkIRect&) const {
     if (fp) {
-        SkScalar yOffset = texture->origin() == kTopLeft_GrSurfaceOrigin ? fSrcRect.y() :
-           texture->height() - fSrcRect.height() * texture->height() / bounds.height()
-                             - fSrcRect.y();
-        int boundsY = (texture->origin() == kTopLeft_GrSurfaceOrigin) ? bounds.y() :
-                      (texture->height() - bounds.height());
-        SkRect effectBounds = SkRect::MakeXYWH(
-            SkIntToScalar(bounds.x()) / texture->width(),
-            SkIntToScalar(boundsY) / texture->height(),
-            SkIntToScalar(texture->width()) / bounds.width(),
-            SkIntToScalar(texture->height()) / bounds.height());
+        SkScalar yOffset = (texture->origin() == kTopLeft_GrSurfaceOrigin) ? fSrcRect.y() :
+                           (texture->height() - (fSrcRect.y() + fSrcRect.height()));
         SkScalar invInset = fInset > 0 ? SkScalarInvert(fInset) : SK_Scalar1;
         *fp = GrMagnifierEffect::Create(texture,
-                                        effectBounds,
                                         fSrcRect.x() / texture->width(),
                                         yOffset / texture->height(),
-                                        fSrcRect.width() / bounds.width(),
-                                        fSrcRect.height() / bounds.height(),
-                                        bounds.width() * invInset,
-                                        bounds.height() * invInset);
+                                        fSrcRect.width() / texture->width(),
+                                        fSrcRect.height() / texture->height(),
+                                        texture->width() * invInset,
+                                        texture->height() * invInset);
     }
     return true;
 }